It's really easy to do, but also really easy to detect:
Gt\ServiceContainer\ServiceNotFoundException - Service can not be located within Container: "Gt\AppLogic\page\_common_php\ContentRepository
This exception mentions _common_php, which is the magic PHP logic file that shouldn't exist in its own namespace, so it's obvious that in this case the developer has put ContentRepository in the go() function parameter, but has forgotten to use App\ContentReposiory at the top of the file.